net: ipc_router: Initialize the sockaddr in recvmsg() handler

sockaddr structure is filled with required information only which
results in few memory locations of structure with uninitialized data.

Memset complete structure before using it to remove uninitialized data.

CRs-Fixed: 2274853
Change-Id: I181710bde100fb1553b925d9fdf227af35ff38b5
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>